pivottabler: Create Pivot Tables in R

Create regular pivot tables with just a few lines of R.
More complex pivot tables can also be created, e.g. pivot tables
with irregular layouts, multiple calculations and/or derived
calculations based on multiple data frames. Pivot tables are
constructed using R only and can be written to a range of
output formats (plain text, 'HTML', 'Latex' and 'Excel'),
including with styling/formatting.